The so-called Office of Tailored Access Operations, or TAO, has benefited the most from the NSA’s expansive mandate, the article reports. It has grown the fastest of all NSA units in recent years and has become the go-to unit to target corporate networks around the world in the name of defending the nation’s security, the article reports.

According to the publication:

TAO’s area of operations ranges from counterterrorism to cyber attacks to traditional espionage. The documents reveal just how diversified the tools at TAO’s disposal have become — and also how it exploits the technical weaknesses of the IT industry, from Microsoft to Cisco and Huawei, to carry out its discreet and efficient attacks.

The article references one of TAO’s sophisticated tools, internally known as “QUANTUMTHEORY”:

A comprehensive internal presentation titled “QUANTUM CAPABILITIES,” which SPIEGEL has viewed, lists virtually every popular Internet service provider as a target, including Facebook, Yahoo, Twitter and YouTube. “NSA QUANTUM has the greatest success against Yahoo, Facebook and static IP addresses,” it states. The presentation also notes that the NSA has been unable to employ this method to target users of Google services. Apparently, that can only be done by Britain’s GCHQ intelligence service, which has acquired QUANTUM tools from the NSA.

The publication also documents another unit called ANT that can call upon a catalog of exploits and backdoors in devices from Cisco, Huawei, Dell, Juniper, Western Digital, Seagate, Maxtor, and Samsung.